[PATCH 6/8] radix_tree: Loop based on shift count, not height
From: Matthew Wilcox
Date: Tue Jan 19 2016 - 09:26:51 EST
From: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
When we introduce entries that can cover multiple indices, we will need
to stop in __radix_tree_create based on the shift, not the height. Split
out for ease of bisect.
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
---
lib/radix-tree.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 422a92a..869be33 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -407,10 +407,10 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
slot = indirect_to_ptr(root->rnode);
height = root->height;
- shift = (height-1) * RADIX_TREE_MAP_SHIFT;
+ shift = height * RADIX_TREE_MAP_SHIFT;
offset = 0; /* uninitialised var warning */
- while (height > 0) {
+ while (shift > 0) {
if (slot == NULL) {
/* Have to add a child node. */
slot = radix_tree_node_alloc(root);
@@ -429,11 +429,11 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
}
/* Go a level down */
+ shift -= RADIX_TREE_MAP_SHIFT;
offset = (index >> shift) & RADIX_TREE_MAP_MASK;
node = slot;
slot = node->slots[offset];
slot = indirect_to_ptr(slot);
- shift -= RADIX_TREE_MAP_SHIFT;
height--;
}
--
2.7.0.rc3